<!DOCTYPE html>
<html lang="zh-CN">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>龙华系统研发中心 - LoongChineOperatingSystem</title>
    <link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/6.4.0/css/all.min.css">
    <style>
        :root {
            --primary-color: #2c3e50;
            --secondary-color: #3498db;
            --accent-color: #e74c3c;
            --text-color: #333;
            --bg-color: #f8f9fa;
        }

        * {
            box-sizing: border-box;
            margin: 0;
            padding: 0;
        }

        body {
            font-family: 'Segoe UI', system-ui, sans-serif;
            background: linear-gradient(135deg, #f8f9fa 0%, #e9ecef 100%);
            color: var(--text-color);
            line-height: 1.6;
            min-height: 100vh;
            display: flex;
            flex-direction: column;
        }

        .header {
            background: var(--primary-color);
            color: white;
            padding: 1.5rem;
            box-shadow: 0 2px 10px rgba(0,0,0,0.1);
            position: relative;
            z-index: 100;
        }

        .nav-container {
            background: rgba(255,255,255,0.95);
            box-shadow: 0 2px 5px rgba(0,0,0,0.1);
            position: sticky;
            top: 0;
            z-index: 99;
        }

        .nav {
            max-width: 1200px;
            margin: 0 auto;
            padding: 1rem;
            display: flex;
            flex-wrap: wrap;
            gap: 1rem;
            justify-content: center;
        }

        .nav-link {
            color: var(--primary-color);
            text-decoration: none;
            padding: 0.8rem 1.2rem;
            border-radius: 8px;
            transition: all 0.3s ease;
            display: flex;
            align-items: center;
            gap: 0.5rem;
        }

        .nav-link:hover {
            background: var(--secondary-color);
            color: white;
            transform: translateY(-2px);
        }

        .nav-link.active {
            background: var(--secondary-color);
            color: white;
        }

        .main-content {
            flex: 1;
            padding: 2rem;
            max-width: 1200px;
            margin: 0 auto;
            width: 100%;
        }

        .section {
            background: white;
            border-radius: 12px;
            padding: 2rem;
            box-shadow: 0 4px 6px rgba(0,0,0,0.05);
            margin-bottom: 2rem;
            animation: fadeIn 0.5s ease;
            display: none;
        }

        .section.active {
            display: block;
        }

        .section-title {
            color: var(--primary-color);
            margin-bottom: 1.5rem;
            position: relative;
            padding-left: 1.5rem;
        }

        .section-title::before {
            content: "";
            position: absolute;
            left: 0;
            top: 50%;
            transform: translateY(-50%);
            width: 5px;
            height: 70%;
            background: var(--secondary-color);
            border-radius: 3px;
        }

        .card-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
            gap: 1.5rem;
        }

        .card {
            background: white;
            border-radius: 10px;
            padding: 1.5rem;
            box-shadow: 0 2px 4px rgba(0,0,0,0.05);
            transition: transform 0.3s ease;
        }

        .card:hover {
            transform: translateY(-5px);
        }

        .form-group {
            margin-bottom: 1.5rem;
            max-width: 400px;
        }

        .form-label {
            display: block;
            margin-bottom: 0.5rem;
            color: var(--primary-color);
            font-weight: 500;
        }

        .form-input {
            width: 100%;
            padding: 0.8rem;
            border: 2px solid #ddd;
            border-radius: 8px;
            transition: border-color 0.3s ease;
        }

        .form-input:focus {
            border-color: var(--secondary-color);
            outline: none;
        }

        .btn {
            padding: 0.8rem 1.5rem;
            border: none;
            border-radius: 8px;
            cursor: pointer;
            transition: all 0.3s ease;
            display: inline-flex;
            align-items: center;
            gap: 0.5rem;
        }

        .btn-primary {
            background: var(--secondary-color);
            color: white;
        }

        .btn-primary:hover {
            background: #2980b9;
            transform: translateY(-2px);
        }

        .footer {
            background: var(--primary-color);
            color: white;
            text-align: center;
            padding: 1.5rem;
            margin-top: auto;
        }

        @keyframes fadeIn {
            from { opacity: 0; transform: translateY(10px); }
            to { opacity: 1; transform: translateY(0); }
        }

        @media (max-width: 768px) {
            .nav {
                flex-direction: column;
                align-items: stretch;
            }
            
            .nav-link {
                justify-content: center;
            }
            
            .main-content {
                padding: 1rem;
            }
        }
    </style>
</head>
<body>
    <header class="header">
        <h1>龙华系统研发中心</h1>
        <p>LoongChineOperatingSystem</p>
    </header>

    <nav class="nav-container">
        <div class="nav">
            <a href="#" class="nav-link active" onclick="showSection('download')">
                <i class="fas fa-download"></i>软件下载
            </a>
            <a href="#" class="nav-link" onclick="showSection('news')">
                <i class="fas fa-newspaper"></i>开发者新闻
            </a>
            <a href="#" class="nav-link" onclick="showSection('forum')">
                <i class="fas fa-comments"></i>技术论坛
            </a>
            <a href="#" class="nav-link" onclick="showSection('projects')">
                <i class="fas fa-project-diagram"></i>项目管理
            </a>
            <a href="#" class="nav-link" onclick="showSection('login')">
                <i class="fas fa-sign-in-alt"></i>用户登录
            </a>
        </div>
    </nav>

    <main class="main-content">
        <!-- 软件下载 -->
        <section id="download" class="section active">
            <h2 class="section-title">软件下载</h2>
            <div class="card-grid">
                <div class="card">
                    <h3>桌面版系统</h3>
                    <p>最新版本：v2.3.1</p>
                    <button class="btn btn-primary" onclick="downloadSoftware('desktop')">
                        <i class="fas fa-download"></i>下载安装包
                    </button>
                </div>
                <div class="card">
                    <h3>移动端系统</h3>
                    <p>最新版本：v1.8.2</p>
                    <button class="btn btn-primary" onclick="downloadSoftware('mobile')">
                        <i class="fas fa-download"></i>下载安装包
                    </button>
                </div>
            </div>
        </section>

        <!-- 开发者新闻 -->
        <section id="news" class="section">
            <h2 class="section-title">最新动态</h2>
            <div class="card-grid">
                <div class="card">
                    <h3>新版本发布</h3>
                    <p>2023年12月 v3.0 预览版发布</p>
                    <p>新增容器化支持，优化内核调度算法</p>
                </div>
                <div class="card">
                    <h3>开发者大会</h3>
                    <p>2024年开发者大会报名开启</p>
                    <p>时间：2024年3月15日-17日</p>
                </div>
            </div>
        </section>

        <!-- 登录表单 -->
        <section id="login" class="section">
            <h2 class="section-title">用户登录</h2>
            <form id="loginForm" class="auth-form">
                <div class="form-group">
                    <label class="form-label">用户名</label>
                    <input type="text" class="form-input" placeholder="请输入用户名" required>
                </div>
                <div class="form-group">
                    <label class="form-label">密码</label>
                    <input type="password" class="form-input" placeholder="请输入密码" required>
                </div>
                <button type="submit" class="btn btn-primary">
                    <i class="fas fa-sign-in-alt"></i>立即登录
                </button>
            </form>
        </section>
    </main>

    <footer class="footer">
        <p>&copy; 2023 龙华系统研发中心 - 版权所有</p>
        <p>联系我们: support@loongchine.com</p>
    </footer>

    <script>
        // 页面切换功能
        function showSection(sectionId) {
            // 更新导航状态
            document.querySelectorAll('.nav-link').forEach(link => {
                link.classList.remove('active');
            });
            event.target.classList.add('active');

            // 切换内容区域
            document.querySelectorAll('.section').forEach(section => {
                section.classList.remove('active');
            });
            document.getElementById(sectionId).classList.add('active');
        }

        // 表单提交处理
        document.getElementById('loginForm').addEventListener('submit', function(e) {
            e.preventDefault();
            // 这里添加实际的登录逻辑
            alert('登录功能演示');
        });

        // 下载功能
        function downloadSoftware(type) {
            const versions = {
                desktop: 'LoongChine-Desktop-2.3.1.iso',
                mobile: 'LoongChine-Mobile-1.8.2.apk'
            };
            alert(`开始下载: ${versions[type]}`);
        }

        // 响应式导航菜单
        window.addEventListener('resize', () => {
            const nav = document.querySelector('.nav');
            if (window.innerWidth < 768) {
                nav.classList.add('vertical');
            } else {
                nav.classList.remove('vertical');
            }
        });
    </script>
</body>
</html>